Molecular interactions between quinoa, the biocontrol agent Trichoderma and the pathogen Peronospora variabilis
Molecular interactions between quinoa, the biocontrol agent Trichoderma and the pathogen Peronospora variabilis
Author
Summary, in English
In this work, the molecular interactions of quinoa with the pathogen Peronospora variabilis, causal agent of the downy mildew disease, and the interactions of quinoa with the beneficial biocontrol fungi Trichoderma harzianum were studied. Experimental systems for interaction experiments were developed and used, followed by morphological, biochemical and transcriptomic analysis. We describe the response of two quinoa cultivars to the infection of P. variabilis under controlled conditions. The quinoa cultivar Kurmi was more tolerant to P. variabilis infection than the Real cultivar, despite the lack of hypersensitive response. The defense response observed in the Kurmi cultivar might be mediated by the jasmonic acid signaling pathway. Cultivars that can trigger hypersensitive response are more resistant to P. variabilis than Kurmi and therefore a better selection for agriculture.
Quinoa in the presence of Trichoderma had variable outcomes depending on the growth conditions. We observed that quinoa growth was promoted in regular soil experiments or by interaction with Trichoderma volatile compounds in axenic co-culture. However, the growth of two quinoa cultivars was significantly inhibited by T. harzianum in axenic co-culture and in steamed soil experiments. The transcriptomic data of the quinoa growth inhibition by Trichoderma suggests activation of molecular signaling very similar to the signaling observed during defense response against pathogens. Further, we observed a specific group of quinoa plant defensins to be more rapidly induced by Trichoderma in a resistant cultivar but not in a susceptible one. These plant defensins showed a recent evolutionary expansion and could play a major role in providing pathogen resistance to certain quinoa cultivars.
In order to protect quinoa from P. variabilis infections by Trichoderma application and enhance the quinoa yields in agricultural systems might be necessary to perform compatibility tests between the Trichoderma biocontrol agents and the quinoa cultivars. These compatibility tests should be performed in regular soil.
Department/s
Publishing year
2019
Language
English
Full text
Document type
Dissertation
Publisher
Lund University
Topic
- Biochemistry and Molecular Biology
Keywords
- Chenopodium quinoa
- Peronospora variabilis
- Trichoderma harzianum
- Molecular interactions
- qRT-PCR
- RNA-seq
- Plant growth promotion
- Chenopodium quinoa
- Peronospora variabilis
- Trichoderma harzianum
- RNA-seq
- qRT-PCR
- molekylära interaktioner
Status
Published
Supervisor
ISBN/ISSN/Other
- ISBN: 978-91-7895-093-5
- ISBN: 978-91-7895-094-2
Defence date
5 June 2019
Defence time
09:15
Defence place
Biology lecture hall, Biology building A, Sölvegatan 35, Lund
Opponent
- Enrique Monte (Professor)